var x : number | string = 123;
x = "abc";
var x1 : string = x.toString ();
console.log (x1);
var x2 : string = x.toLocaleString ();
console.log (x2);
var x3 : string = x.toUpperCase ();
console.log (x3);
var x4 : string = x.toLowerCase ();
console.log (x4);
